India, Oct. 15 -- Netflix's The Diplomat returns with another season of political deception, diplomatic tensions and difficult personal choices. Starring Keri Russell as Kate Wyler and Rufus Sewell as Hal Wyler, Season 4 picks up after Kate discovers that US President Grace Penn and Vice President Hal have secretly stolen Poseidon, a devastating Russian weapon recovered from a submarine off the UK coast. Their decision threatens America's relationship with Britain and puts the future of their alliance at risk.

However, the stolen weapon is only one part of the growing crisis. Kate must also deal with Hal's decisions, the death of British Foreign Secretary Austin Dennison and Grace's increasingly aggressive approach to international diplo...